1. Field of the Invention
The present invention relates to decorative laminated non-slip liners or mats, and more particularly to an improved decorative laminated non-slip liner or mat which avoids delamination, has a lay-flat characteristic when unrolled, and has a smooth decorative surface with no discernable visual or physical surface discontinuities transferred from the underlying substrate. The laminate may be substantially non-adhering to certain susceptible finished surfaces.
2. Description of the Prior Art
Prior art decorative non-slip liners utilize frictionalizing materials foamed on a coated scrim. Such frictionalized material is then permanently laminated to a printed vinyl substrate.
The primary disadvantage of the prior art concerns the frictionalizing material layer used within the lamination process. As an example, reference is made to U.S. Pat. No. 5,707,903 to Schottenfeld. The frictionalizing material layer of Schottenfeld is created by the submersion of woven or knitted scrim in polyvinyl chloride (PVC) foaming compound. The substrate is then exposed to heat, activating blowing agents within the compound and curing the foaming compound about the framework of yarns making up the woven or knitted scrim. The inherent nature of this process is the formation of an uneven surface on both sides of the frictionalizing material layer (see FIG. 3 of Schottenfeld). The primary drawback of the frictionalizing medium is that this random uneven surface, coupled with the pattern formation of the foamed polyvinyl chloride (PVC), will visibly and physically penetrate through to the attached laminated vinyl layer, resulting in a displeasing, irregular appearance of the final product.
Another problem with the prior art is that the frictionalizing compound contains a plasticiser, i.e. an oil, used to solvate the polyvinyl chloride (PVC) resin. Plasticiser is a key ingredient within the non-slip composition, and is known to migrate within the substrate after it has been cured. The migration of this component will break down the bonding qualities of the adhesive utilized to affix a vinyl sheet to the foamed non-slip substrate. The inherently uneven face of the coated material provides limited surface area to effect a bond. This, coupled with the decomposition of the adhesive, results in eventual delamination of the two substrates. The adverse effects of plasticiser that remains active after curing also have been known to cause marring of finished surfaces covered by the liner, including lacquers, oil-based paint finishes and linoleum
Yet another shortcoming of the prior art relates to its layflat characteristics. The inherently unbalanced construction of the materials presently used in the prior art prevents them from initially conforming to a flat surface (again referencing FIG. 3 of Schottenfeld), while the liner will curl in upon itself when removed from tubular packaging. This is a common phenomenon for laminated substrates of dissimilar thickness, intensified by the migratory shrinking action of adhesive, which will cure further after the lamination process. Although some adhesives have been developed to resist the adverse reaction of plasticisers, it should be noted that the physical properties of foamed PVC scrim laminated to a decorative vinyl layer will still cause the product to retain an initial roll set or memory.
Another related reference of prior art is U.S. Pat. No. 4,137,356 to Shoemaker et al. (Shoemaker). The Shoemaker place mat is constructed of a paper or plastic sheet upon each side of which is imprinted a pattern of high friction material. However, the top surface of the Shoemaker place mat is not a decorative surface, is not of laminated construction, and does not exhibit a smooth top surface, i.e., it has a number of projections effective in imparting anti-skid and anti-slip characteristics to the top of the mat to reduce slipping or skidding of glasses, dishes, and the like placed thereon.
A number of other prior art activities have addressed the issue of preventing slippage of items such as place mats, liners, and the like. In U.S. Pat. No. 5,845,144 Hawley discloses use of a frictionalizing layer of a cured aqueous dispersion of polyurethane foam, to provide a closed cell undersurface. However, such foamed polyurethanes are less durable, being subject to rolling off or rubbing damage during use and cleaning, which can lead to wrinkling and creasing of the liner or mat with normal usage. Also, its electrostatic properties attract dust and grime. Accordingly, the need remains for an improved decorative non-slip liner.